雪氷チーム

Snow and Ice Research Team

斜風対応型吹き払い柵の開発
Blower Snow Fence for Winds with a Broad Angles of Incidence
積雪寒冷地における上下二車線の道路には路側に設置可能な吹き払い柵が用いられることが多くあります。しかし、吹き払い柵は風が柵に対して斜めから入射した場合や、積雪により下部間隙が狭められた場合に、防雪効果が低下することが明らかとなっていました。
そこで寒地土木研究所では、従来柵と同様に道路敷地内に設置可能で、風が斜めから入射する場合や柵下部間隙の閉塞時においても著しく防雪効果が低下しない斜風対応型吹き払い柵を開発しました。
（特許番号：5610251）
Along two-lane roads in snowy cold regions, a "blower snow fence", which can be installed at the immediate roadside, isfrequently used. However, it was clarified that the snow-control performance of the blower snow fence decreases when
the incident wind is oblique or when the bottom clearance of the fence is narrowed by snow accumulated below the fence.
To solve such problems, the Civil Engineering Research Institute for Cold Region has developed a blower snow fence forwinds with a broad angles of incidence in the right of way in a similar way to that of conventional snow fences but whosesnow control performance does not markedly decrease even when the incident winds are oblique or when the bottom clearance is blocked. (Patent Number: 5610251)

概要特Overview

The blower snow fence for winds with a broad angles of incidence is a fence made oflong vertical snow control plates with a v-shaped cross-section butted close together. Thefence mitigates visibility hindrance by using slanted snow control panels to divert thewind downward. Strong winds blowing through the bottom clearance of about 1m inheight blow snow from the road. The fence can be installed at the immediate roadside.

野外観測による実証試験

Demonstration experiment by onsite observation
斜風対応型吹き払い柵の防雪機能を確認するため、実物大の柵を約50m製作し、野外フィールドに設置して実証試験を行いました。
その結果、斜風対応型吹き払い柵は従来型の柵と同等以上の防雪機能を有し、風が斜めから入射した場合でも効果を発揮することが確認できました。
To verify the snow control performance of the blower snow fence for winds with a broad
angles of incidence, a full-scale fence of about 50m in length was produced, and ademonstration experiment was done by installing the fence in the field.
The experiment clarified that the blower snow fence for winds with a broad angles ofincidence has an equal to or greater snow control performance than that of theconventional snow fence and that the fence was effective even in oblique winds.
Visibility improvement rate(視程障害緩和効果)

視程改善率(%)

7,686

1000

1

Snowdrifts do not form easily on the road, because the fence accumulates snow
on its windward side when the bottom clearance is blocked.

●従来型●斜風対応型吹き払い柵

The blower snow fence for winds with a broad angles
of incidence

Conventional fence②

吹きだまりを形成①

・下部間隙非閉塞時- When the bottom clearance - When the bottom clearance
is not blockedis blocked

下部間隙が閉塞1.When the bottom clearance is blocked
2.Snowdrifts form.
下部間隙が塞がると、道路上に吹きだまりを形成する。

道路上の雪粒子を吹き払う

柵風上に雪粒子を捕捉

When the bottom clearance is blocked,snowdrifts form on the road.

The wind blows the snow
particles off the road.

The fence traps the snow
particles on its windward side.

特長Advantage

2

凹凸状防雪板の採用により、斜めから入射した風を下方向に誘導。
The v-shaped snow control plates divert oblique incident winds downward.

縦張りに設置した凹凸状の防雪板は、斜めから入射した風を下部間隙に導くことが可能です。

The vertical v-shaped snow control plates divert oblique winds to the bottom clearance.
●従来型の防雪板●新型柵の防雪板（凹凸状）- Conventional snow control panel- Newly developed snow control plate (v-shaped)

風最大値
Max（上側:Top）

75%タイル値

風を逃がさず誘導することが75th percentile

中央値

100

100<= >200

0-100

200<= >500 500<= >1000

100<= >200

200<= >500 500<= >1000

最小値

Newly developed fence

従来柵

風速比1.0以上で効果有り
Effectiveness has been verified for wind speed ratios of 1.0 or greater.

3.09

特長Advantage

3

防雪板を支柱から離して設置するため、下部間隙の機械除雪が容易。
Mechanized removal of snow at the bottom clearance is easy because the snow
control plates are installed at a certain distance from the supporting pillars.
柵端と支柱の距離が長い

The distance between the plates andthe supporting pillars is great.

最大値
Max

1.5（下側:Bottom）

新型柵

新型の方が向上している
The newly developed fence has improved performance.

3.07

There is less snow blowing effect.

Min

Conventional fence▲実証試験結果(視程障害緩和効果)
The result of the demonstration experiment (effectiveness in visibility hindrance mitigation)(吹き払い効果)The plate can redirect all
the wind downward.

風が横に逃げる

25th percentile

Wind incident angle

Wind incident angle
0-100

25%タイル値

風向角45.0°

Visibility at the control point

2.0

可能Median

風向角67.5°

10・下部間隙閉塞時

2,652

基準点視程(m)Wind speed ratio

下部間隙閉塞時に柵風上側に雪を溜めるため、道路上に吹きだまりを生じさせない。

Advantage

斜風対応型吹き払い柵は凹凸状に加工した縦長の防雪板を横方向に隙間無く列設した防雪柵です。傾斜した防雪板で風の流れを下向きに変え、視程障害を緩和します。同時に、高さ1ｍ程度の下部間隙から吹き出す強風により道路上の雪を吹き払います。
また、路側に設置可能です。

風速比

長75%タイル値

75th percentile

1.0

中央値

0.5

25%タイル値

0.0

最小値

サイドウイング
Side Wing

Median25th percentile

67.545.0

風向角（度）
Wind incident angle (degree)

Min

新型柵

Newly developed fence

従来柵

Conventional fence▲実証試験結果(吹き払い効果)
The result of the demonstration experiment(effectiveness in snow blowing)▲現地観測状況
The fence under onsite
observation

安全・快適

北の道

Safe, pleasant driving on Northern Roads

サイドウイングが支柱と接触せず、機械を使用した効率的な除雪が可能です。

防雪柵の下部間隙の開放により、吹き払い機能が回復します。

The clearance between the plates and the supporting
pillars makes it possible for snow to be efficiently
removed by snowplow.

The snow control performance ofthe fence is restored by reopening
the bottom clearance.

国立研究開発法人土木研究所 寒地土木研究所

National Research and Development Agency Public Works Research Institute Civil Engineering Research Institute for Cold Region